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pt3: mask/cache note_command bottom nibble

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adds 8 cycles but removes a number of instructions
This commit is contained in:
Vince Weaver 2019-06-05 00:26:12 -04:00
parent 6334ad394c
commit c623d5c0bb
1 changed files with 33 additions and 34 deletions
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67
pt3_player/pt3_lib.s
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@ -15,6 +15,7 @@
; + 3203 bytes -- combine common code in note decoder
; + 2937 bytes -- qkumba first pass
; + 2879 bytes -- qkumba second pass
; + 2839 bytes -- mask note command in common code
; TODO
; move some of these flags to be bits rather than bytes?
@ -220,6 +221,7 @@ temp_word_h: .byte $0
note_command: ; shared space with sample_b0
sample_b0: .byte $0
note_command_bottom: ; shared space with sample_b1
sample_b1: .byte $0
; Header offsets
@ -1124,6 +1126,9 @@ note_decode_loop:
; get next value
lda (PATTERN_L),Y ; 5+
sta note_command ; save termporarily ; 4
and #$0f ; 2
sta note_command_bottom ; 4
lda note_command ; 4
; FIXME: use a jump table??
; further reflection, that would require 32-bytes of addresses
@ -1141,8 +1146,7 @@ decode_case_0X:
; $0X set special effect
;==============================
; -1
lda note_command ; 4
and #$f ; 2
lda note_command_bottom ; 4
; we can always store spec as 0 means no spec
@ -1180,8 +1184,7 @@ decode_case_1X:
; 5
; -1
lda note_command ; 4
and #$0f
lda note_command_bottom ; 4
bne decode_case_not_10 ; 3
decode_case_10:
@ -1215,7 +1218,7 @@ decode_case_3X:
bcs decode_case_4X ; branch greater/equal ; 3
; -1
lda note_command ; 3
adc #$e0 ; 2
adc #$e0 ; same as subtract $20 ; 2
sta pt3_noise_period ; 3
jmp done_decode ; 3
@ -1229,8 +1232,7 @@ decode_case_4X:
; cmp #$40 ; already set ;
bne decode_case_5X ; 3
; -1
lda note_command ; 4
and #$0f ; set ornament to bottom nibble ; 2
lda note_command_bottom ; set ornament to bottom nibble ; 4
jsr load_ornament ; 6+93
jmp done_decode ; 3
@ -1262,49 +1264,48 @@ decode_case_bX:
; $BX -- note length or envelope manipulation
;============================================
; cmp #$b0 ; already set from before
bne decode_case_cX
lda note_command
and #$f
beq decode_case_b0
sbc #1 ; envelope_type=(current_val&0xf)-1;
bne decode_case_bx_higher
bne decode_case_cX ; 3
; -1
lda note_command_bottom ; 4
beq decode_case_b0 ; 3
; -1
sbc #1 ; envelope_type=(current_val&0xf)-1; ; 2
bne decode_case_bx_higher ; 3
decode_case_b1:
; Set Length
; get next byte
iny
lda (PATTERN_L),Y
iny ; 2
lda (PATTERN_L),Y ; 5
sta note_a+NOTE_LEN,X
sta note_a+NOTE_LEN_COUNT,X
bcs done_decode ; branch always
sta note_a+NOTE_LEN,X ; 5
sta note_a+NOTE_LEN_COUNT,X ; 5
bcs done_decode ; branch always ; 3
decode_case_b0:
; Disable envelope
sta note_a+NOTE_ENVELOPE_ENABLED,X
sta note_a+NOTE_ORNAMENT_POSITION,X
beq done_decode
sta note_a+NOTE_ENVELOPE_ENABLED,X ; 5
sta note_a+NOTE_ORNAMENT_POSITION,X ; 5
beq done_decode ; 3
decode_case_bx_higher:
jsr set_envelope ; 6+64
bcs done_decode ; branch always
bcs done_decode ; branch always ; 3
decode_case_cX:
;==============================
; $CX -- set volume
;==============================
cmp #$c0
bne decode_case_dX
lda note_command
and #$0f
bne decode_case_cx_not_c0
cmp #$c0 ; 2
bne decode_case_dX ; 3
; -1
lda note_command_bottom ; 4
bne decode_case_cx_not_c0 ; 3
; -1
decode_case_c0:
; special case $C0 means shut down the note
@ -1327,8 +1328,7 @@ decode_case_dX:
cmp #$d0
bne decode_case_eX
lda note_command
and #$0f
lda note_command_bottom
bne decode_case_dx_not_d0
;========================
@ -1364,8 +1364,7 @@ decode_case_fX:
sta note_a+NOTE_ENVELOPE_ENABLED,X
; Set ornament to low byte of command
lda note_command
and #$f
lda note_command_bottom
jsr load_ornament ; ornament to load in A
; Get next byte